Sökning: "Direct-Sequence Code Division Multiple-Access DS CDMA . multirate"

Hittade 5 avhandlingar innehållade orden Direct-Sequence Code Division Multiple-Access DS CDMA . multirate.

  1. 1. Successive Interference Cancellation in DS-CDMA Systems

    Författare :Ann-Louise Johansson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; group-wise detection; direct-sequence code division multiple access DS-CDMA ; multiuser detection; multirate schemes; weighted cancellation; successive interference cancellation;

    Sammanfattning : There is every indication that direct-sequence code division multiple access (DS-CDMA) will be one of the multiple access schemes for the third generation wireless mobile systems. CDMA is a flexible multiple access method suitable for supporting many new services (speech, data, video, etc), which are becoming increasingly important for mobile communications. LÄS MER

  3. 2. Multirate Schemes and Multiuser Decoding in DS/CDMA Systems

    Författare :Tony Ottosson Gadd; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multi processing-gain; multi-channel; soft decoding; vector quantization.; joint optimization; Direct-Sequence Code Division Multiple-Access DS CDMA . multirate; multi-modulation; multiuser detection;

    Sammanfattning : Direct-Sequence Code Division Multiple-Access (DS/CDMA) has for some yearsbeen considered as a candidate for future personal and mobile communications.The reasons are mainly the properties of universal frequency reuse andthe multi-path mitigation. LÄS MER

  4. 3. Coding, Decoding and Multiuser Detection for Wireless CommunicationsCoding, Decoding and Multiuser Detection for Wireless Communications

    Författare :Pål Orten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; direct-sequence code division multiple access DS-CDMA ; sequential decoding; Rayleigh fading; multirate DS-CDMA; optimum distance spectrum; rate matching; rate compatible punctured convolutional codes; multiuser detection; nested codes;

    Sammanfattning : In the strive for making the Universal Mobile Telecommunication System(UMTS) a reality, concepts and techniques are to be developed which canprovide both high system capacity and sufficient quality for the increasingnumber of mobile users. To obtain these objectives, powerful and flexibleerror control coding is needed, as well as efficient means for many usersto share the same commmication medium. LÄS MER

  5. 4. Multirate Codes and Multicarrier Modulation for Future Communication Systems

    Författare :Pål Frenger; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; channel estimation; code-spread CDMA; DS-CDMA; convolutional codes; interference cancellation; nested convolutional codes; multicarrier modulation; optimum distance spectrum ODS ; rate-compatible punctured convolutional codes RCPC-codes ; OFDM; turbo decoding; rate matching; parallel combinatory signaling; Rayleigh fading;

    Sammanfattning : In this thesis, new detection and modulation methods for multicarrier systems are presented. The proposed multicarrier detectors are based on feedback of previously detected symbols and the idea is to exploit the correlation, both in time between consecutive symbols, and in frequency between neighboring sub-carriers. LÄS MER

  7. 5. Channel Coding and Multiuser Detection for CDMA and Wireless Communications

    Författare :Pål Orten; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rate compatible punctured convolutional RCPC codes; optimum distance spectrum ODS ; low-rate convolutional codes; interference cancellation; code-division multiple-access CDMA ; sequential decoding; automatic repeat request ARQ ; multiuser detection; maximum free distance MFD ; nested convolutional codes; tailbiting; rate matching;

    Sammanfattning : Next generation wireless communication systems will require support for many different applications as well as improved quality compared to existing second generation systems like GSM (Global System for Mobile communications). Since there will be more users and higher data rates, the capacity must also be increased. LÄS MER